Just think about it. If it was not so, why would we be ever bothered about SPAM? SPAM Mails, unsolicited Messages, crank Calls, unwanted Mailers. There is so much Marketing Junk that reaches each one of us, that we could probably be using 5 times less energy and save as much in time.
Recently, I saw a software product in an exhibition which will send companies the name and contact details of the person who did even as much as just browse their website. They said we take it from Hoovers and its likes. So now even the Corporate World is not spared.